Conventionally, for a light source of a light emitting diode type used in a light unit for inspection of products or the like, in order to improve the light convergence performance, a bullet-shaped lens to converge the light emitted by a light emitting element is arranged, or a reflector that reflects the light near the light emitting element toward the direction of light emission is arranged near the light emitting element.
However, with light emitting diode units of the above-mentioned arrangement, since the irradiated light from the light emitting element reflects and travels inside the lens portion of the light emitting diode unit, or travels toward the direction of the light emission in a manner other than that would occur from a point source of light, the light emitted from the light emitting element can not be parallelized to travel toward a certain direction and the light can not be converged by, for example, a conventional converging lens, resulting in a problem that prevents a large amount of light from being irradiated upon a small area. In addition, there is a problem that some light irradiated from the light emitting element is irradiated in vain, such that laterally irradiated light is not utilized. Furthermore, although more light can be obtained from the light emitting element by increasing the amount of electric current, an undesirable release of heat energy is thereby increased drastically, causing rapidly deterioration of the light emitting element.
The present claimed invention mainly intends to solve the above-mentioned problems and to provide a high performance light emitting diode unit that can converge the light irradiated from the light emitting element without loss, and that can easily irradiate a large amount of light upon a small area.